I have done a lot of indoor sports.

Always had low light, moving subjects, and humidity problems.

Be careful when changing your lenses in these environmental changes as they can create condensation on your sensor.

Make sure to let your equipment warm up or cool down before removing it from your case.

F4 is not going to let you get the results you want. The 70-200 f2.8 is made for this action sport, but there are times when the 2.8 is not fast enough to avoid

motion blurr.

If in doubt push the ISO to get the shot. Grain is acceptable motion blurr is not.

The 70-200 2.8 ( I use the nonIS) is my go to for indoor low light motion sports.

I have used the 135 2.0 with terrific results, but felt confined by the focal length for moving sports.

Used the 135 mainly with diving and wrestling. It's results are stunning when you catch the right depth of field.

Also I use single point autofocus with Al Servo.

Bottom line: Get the 70-200 2.8

Thanks